Ignition device for fuel burners



Nov. 8, 1932.

c. B. CHANDLER 1,887,230 IGNITION DEVICE FOR FUEL BURNER Filed April 18, 1925' 2 Sheets-Sheet l IM/ZKM Nov. 8, 1932. CHANDLER 1,887,230

IGNITION DEVICE FOR FUEL BURNERS I Filed April 18, 1925 2 Sheets-Sheet 2 E I a,

i n a be. I 55 I 7.0 32 7.0 I l9 13 as T1 22 Fla 6 INVENTOE Patented Nov. 8 1932 CARL B. CHANDLER, OF HAVANA, ILLINGIS IGNITION DEVICE FOR FUEL BU'RNERS Application filed April is, 1925. Serial m. 24,042.

"his invention relates to ignition devices for oil burners.

The object of the invention is in the: pro

vision of a spark ignition device for domestic oil burners. V V

Another object of the invention. is in the provision of spark ignition mechanism utilized in connection with a domestic oil burner of the so-called revolving cup type, said spark ignition mechanism being located in connection therewith ina manner to automatically prevent the accumulation of carbon.

Still another object of my invention is in f the provision of a spark ignition mechanism for the revolving atomizer type of domestic oil burner, said spark ignition mechanism being fashioned in such manner as to cause almost iustantaneousignition of the atomized fuel mixture upon commencement of operation of the burner.

A further'object of the invention is in th provision of spark" ignition mechanism for the, revolving atomizer type of domestic 7 oil burner, wherein an electrode is disposed ad jacent the rotating atomizing cup in a manner to preventthe accumulation of carbon thereon.

A still further'obj ect of the invention is in the provision ofa spark-ignition mechanism for the revolving atomizer type of oil burner,

wherein the sparking device co-operates with the atomizingmechanism to cause substantially instantaneous ignltion of the pro] ected fuel mixture.

Yet a further object of the invention is in, the provision of a spark ignition device for. use in: connection with the well known domestic oil burner and automatically operatedmechanism for withdrawing the spark ignition device away from-the combustion area. V

Gt-hen obj ects' of myinvention will appear in the following specification-taken inconnection with the annexed drawings, in whicln- Fig. 1 is a diagram of the electricalcir- Fig; 2 is adetail showingin side elevatio of the spark ignitionmechanis'm;

' ture, it is true; but notas'quickl'y as wasdevofthe burner. It might be sai-diat this time,

Fig. 3 is a plan view of Fig. 2, taken on the lines 33 Fig. l is. a detail showing of the float or. timing element;

Fig. 5 is a side-elevation in broken section, 5

of the fuelburner and fuel supply means;l

' and Fig. 6 is a cross-sectional view on the line 66 of Fig. 4. 1

Referring t'o'the drawings, 1 have disclosed a domestic oil burner of theso-called rotary atomizer type, and although my spark igni tion device, as far as the automatic mecha-' nism for withdrawing same. from the combustion area is concerned, might be applied 5 as well to any of the well known types of oil burners, nevertheless, my present spark ignition mechanism'is peculiarly adapted to the present disclosed type of burner.

be well to say that the prior art discloses spark ignited domestic oil burners with'various locations .of the spark plug to the dis charged fuel mixture. I V

Applicant has also utilized spark plug mechanismfor igniting the projected fuel mixture in the type of oil burning device dis-, closed in thedrawing's. i

It was to overcome the difiicultiesthat attended the ordinary use of'a spark plugto ignite the discharged fuel 'mixture that prompted" the present spark ignition device. Prior to the development of the present structure, applicant, as did. other manufacturers, projected electrodes of a'sparkingdevice into the path of the fuel mixture that atomizing' cup.

The above mechanismignited the fuel miX- sired, nor did such location of 'the'spark prevent accumulation of carbon" and hence necessitvfor SeIY1C1I1'g, cOntlhually, this part hat although carbondeposit ona spark plug exposed'to the combustion area would be burnedoif 'during'the burning operation, nevertheless any accumulationof liquidfuel upon thesparkingdevice, when expo'sed to the tremendous-heat in thecombustion chain Before continuing the description, it mightv 9' ber and not during the burning action, would result in carbon. It was to overcome this a carbon deposit as well as to increase the efiiciency of the ignition medium that sponsored the following mechanism.

Inasmuch as the present application is directed to the ignition mechanism, only a general description will be given of the fuel burning device which is descriptive of :1 Well known class of domestic oil burners. The operatlve port1ons of the present burner are assembled as showmivithin the combustion chamber of any conventional furnace.

, augmented by the air circulating at the edge of said cup. Means for rotatingthe cup 11 j is provided in a vertically disposed shaft 15,

suitably supported in a formalsupport 16,

and bearing 17. A formal electric motor 18 is adapted to drive the shaft 15, through the friction connections'19 and 20. Also assembled in an operative position with relation to the electric motor, is a. conventional pump 21, adapted upon operation of the motor to draw fuel from a supply tank 22, through appropriate lead 23, and deliver fuel through the above mentioned tube 12, to the rotary a-tomizing cup. A needle valve 24, in the delivery. tube 12, provides means for adjusting the fuel feed.

Another adjustment mechanism for the a burner is provided in an adjustable supporting screw and bracket mechanism 25, for the electric motor, making possible an option speed of the rotary cup, due to the varying of the position of the friction elements 19 and 20. Fuel withdrawn by action of the pump 21 that is in excess of the amount required by the fuel pipe 12, is returned through the pipe 26, to the main fuel supply tank 22.

The spark ignition mechanism which forms the basis for the present application, will be of the timing mechanism therefor. It is desirable that the ignition means operate merely upon a commencement of the operation'of the burner, and then but temporarily. To accomplish the above result, I have provided a mechanically acting means I controlled bythe fuel flow, made up of the following elements. 7

A hearth 10, is suitably supportedin the combustion chamber of the furnace ama) bracket 33, as well as the inlet and outlet pipes thereto, said devices being both in the above described return fuel line 26. The container 32, has a fuel inlet 34:, discharging fuel during the operation of the device into a projecting through the upper side of the container 82. An overflow from the float chamber is shown at 41, saidoverflow connecting with the main outlet 42, as well as the fuel discharge normally passing through the main opening controlled by the adjustable screw 86. The projecting end of stem 40, of the float 39, has a loose connection 43, with a movable electrical contact arm 44. This contact arm 4 f, influenced by the action of the float member, is adapted to op-. 'erate a mercury bulb having the contact points 5 and 4:6. This mercury bulb is adapted to control the circuit of the sparking device, the operation of which is now to be described. 7

My presentspark ignition deviceincludes a single electrode 50, disposed in a vertical manner adjacent the atomizi'ng cup 11', the upper end of which is bent at a point slightly above the lower edge of the atomizing cup, and the remaining short and sharpened end of the electrode projectsdownwardly to a point adjacent the rim of the said lower edge of the atomizer. This sparking end of the electrode is disposed not radially but in an angular relationship to the radius of the rotary atomizing cup and is set'for a sparking gap between the tip thereof and the edge of the rotating cup of about of an inch. Direction of rotation, as indicated by arrow in Fig. 3 of the drawings,,shows that the 10- .cation of the electrode above described is such that the tangential discharge of fuel mixture from the swiftly moving atomizer is such that the spray therefrom will strike the electrode in a manner to be concentrated or enriched at the spark gap. 'This con centration or enri'ching of the fuel, mixture is due to the angular relation between the described in detail following a description electrode and the radius of the cup and the slight elevation of the bent portion thereof,

above the edge of the rotating cup. As a matter of fact, the actual spark gap is slightly below the tangential spray, but this assists in quick ignition for the reason thatthe projectlng fuel mixture, after striking a the bent portion ofthe electrode, is forced downwardly towards the spark gap where it is concentrated or enriched and ignited at a point out of the main blast.

It is obvious that the revolving cup forms the ground for the spark. The electrode 50 has a removable mounting 51, namely abrass friction strip, with the main electrode 52 to permit ready removal and assembly.

The electrode 52 is bent to permit possible and practical insertion in the housing member 53, said electrode being embedded in a. formal porcelain insulator 54, which is retained in a supporting member 54, the same being slidably mounted in the housing 55. The bending of the electrode 52 at the point 50 is to prevent the possible gravitation of fuel into the housing 53 and hence carbonizing the plug. The housing member is bracketed as at 56 to the pedestal 57 of the burner and is open at the endto permit insertion therein of the plug, there being a slot 58 at,

the upper end portion to permit insertion of the bent portion of the electrode as well as a slight reciprocatory movement. 'Means for closing the upper end ofthe housing 55,.

after insertion of the plug, is provided in a cap 59. Proper location of the spark plug within the housing and means for guiding the movement thereof is provided in a slot 60 in the housing 55 and a set screw 61 adapted to be slidable in the slot as well as to be inserted in the portion 54 of the plug from the outside.

Securely attached to the wire connecting end 62 of the spark plug is a connecting member 63, said member 63 being attached by means of the insulated portion 64 with the core 65 of a solenoid 66. :A bracket 67 is provided for attachment of the solenoid to the pedestal.

The mechanical means for timing the spark has already been described, and the electrical connections for the ignition mechanism are as follows: Wires 68 and 69 carry the line voltage to a formal transformer 70. Fromthe low voltage side of the transformer 70 is the grounded wire 71, the other side of the low voltage circuit 72 passing through'a for= mal spark coil 7 3, the above described mercury bulb containing the contact points 45 and 46, and finally being connected at the point 62 with the peculiar spark. plug or ignition member. As previously described, the ground for the electrode 50 is the rotating cup. 7

The mechanism controlling the operation of the solenoid and hence the reciprocation of the sparking member is provided partly in the float mechanism previously described. In other words, the movement of the lever 40 on the float member operates upon the op posite side a similar mercury bulb having the contact points 74 and 7 5 therein. Similarly, movement of the float operates, after a determined time, to open the electrical circuit through the mercury bulb. The electrical.

transformer 78; On the low voltage side ofthe transformer 78, one wire 7 9-leads to the mercury bulb which is adapted to be operated by thefloat mechanismand the other wire 80 is carried through the solenoid 66 and finally to the mercury bulb. V

The operation of the device is as follows: Upon commencement of operation of the burner, an atomized fuel mixture is projected tangentially from the rim of the rotating cup. Thisinitial operationof the burner results in the completion of the electrical cir- I cuit to the solenoid as well as completingthe electrical circuit to the sparking member.

The action of the solenoid, due to theupward movement of the core therein, raises" the sparking mechanism, and hence the electrode 50, to a point adjacent the rotating cup of the burner. Simultaneous completion of the electrical circuit to the electrode results'in a continuous spark acrossthe gap between the ment of same to the ignition point results in a rich mixture for ignition purposes; and

hence, an almost instantaneous ignition of the atomized fuel. It might also be said that the fact that the spark itself is just below the discharging fuel mixture, rather than directly in the cone of same, prohibits the blowing out of theinitial ignited fuel mixture, and thus 385 sists quick ignition.

Once the burner is ignited, means has been provided for withdrawing the=electrode50 from out the combustion area. This mechanism is timed similarly to the timing of the spark ignition, namely, by the floatmechanism. After a determined time, or more specifically, when the float reaches anelevated position, the two mercury bulbs containing the respective contacts 45, 46, 74 and 75, are

moved to a position whereby the electrical circuit is opened in the bulbs, thus cutting off the electrical circuit to the sparking device, as well as de-energizing the solenoid- This de-energizing of the solenoid results in a dropping of the core and consequent downward movement of the electrode 50, from out the combustion area.

The reason for the withdrawal of theelectrode after ignition isto prevent al t ntir'ely the accumulation of carbon upon same. While the electrode projects into the cone of discharging fuel mixture, a small portion of said mixture is deflected from the combustion area, collecting upon the electrode and gravitating downward thereon. Carbon results from the exposure of unatomized fuel to intense heat, hence, to prevent this accumulation of carbon, as well as the continued exposure of the electrode to the direct flame of the burner, the above described means for withdrawing same has been devised, and it might also be stated that the washer 81 is attach'ed to the electrode at a point a short dis- I 1 tance from the sparking end thereof, the same being adapted to catch any unatomized fuel that collects upon the electrode, and to suspend same so closely to the combustion area that it will be entirely burned off.

Again, with respect to the matter of carbon,

- applicants sparking device is absolutely prevented from collecting carbon at the sparking point, due to the fact that it is located, during tion, a combustion chamber, means for proect1ng an atomized fuel mixture therein com- 1 prising a rotating cup member, a sparking member for igniting said fuel mixture, in-.

cluding a sparking point located adjacent the periphery of the rotary cup member and at a spaced interval therefrom, a rearwardly extending portion disposed in the path of the fuel mixture and adapted to divert a portion thereof into the sparking gap in a manher to enrich the mixture at the sparking point, and a cup member disposed a substantial distance below the sparking member in a manner to trap the unburned condensed fuel mixture and to hold the same in close proximity to the ignited'fuel mixture.

2. In a fuel burning device, in "combination, a combustion chamber,meansfor projecting an atomizedfuel mixture therein, comprising a rotating cup, means for igniting said fuel mixture including an electrode fashioned to provide a spark gap between the contact point thereof and the periphery of the rotating cup, andmeans controlled by the operation of the burner for advancing theelectrode into the combustion. area upon 'thecommencement of operation of the burner and automatically controlled mechanism for withdrawing same from the combustion area after a sufficient period for'ignition.

3. In a fuel burning device, in combination, a combustion chamber, means for projecting a fuel mixture therein, comprising a rotating cup member, sparkignition mechanism for igniting said fuel mixture, said mechanism including an electrode located adj acent the rotatingcup in such manner that said cup forms a ground for the electrode, a

mixture divertingmember formed as a part of the electrode, said member being elevated above the rotating cup and inthe' path of the'fuel mixture in such manner as to project a portion thereof into the spark gap to enrich the mixture at said point.

4. lhe combination with a fuel burner, of electrically power driven means for discharging a fuel mixture into a zone of ignition, a combustion chamber, spark ignition mechanism and means automatically controlled by the operation of the burner for advancing and withdrawing said spark ignition mechanism from the zone of ignition, said means including electrically operated mechanism controlled by the operation of the electricallypower driven means 5. In combination, with an oil burner,'of electrically powerdriven means for discharging a fuel mixture into azone of ignition, a combustion. chamber, sparkignition mechaism and means comprising mechanism automatically controlled by the operation of the burner for advancing and withdrawing said spark ignition mechanism from the zone of ignition.

6. In combination with an oil burner, of power driven means for discharging a fuel mixture into a zone of ignition, a combustion chamber, an ignition member, and means comprising mechanism automatically controlled by the operation of the burner for advancing and withdrawing said ignition member from the zone of ignition.

7 In combination with an oil burner, of electrically power driven means for discharging a fuel mixture into a zone of ignition, acombustion chamber, spark ignition mechanism and means comprising mechanism automatically controlled .by the operation of the burner for advancing said spark ignition mechanism into the zone of ignition, and

mechanism automatically controlled by the operation of the burner for withdrawing said spark ignition mechanism from the zone of ignition.

8. In a fuel burning device, in combination, a combustion chamber, means for pro-;

jecting a fuel mixture therein comprising a rotatable cup member, power means for driving said cup member, a friction connection between the cup member and the power means, and spark lgmtion mechamsm com-- prising an electrode disposed adjacent the edge of said cup member in a manner to form a spark gap thereb'etween, said electrode having a portion thereof disposed in the path of the projected fuel in a manner to divert ;a portion of the fuel'mixture into the spark CARL B. CHANDLER. 

